It's not the base frequencies that matter, it's the harmonic sequence above the base note that makes for the difference between instruments.
Play with it yourself - record various notes, on various instruments, do the FFT to break it into the frequency domain, and you'll see quite a few harmonics over the base note. Strip those out, and it sounds muddy.
For those old enough, an analog phone line was typically limited to 300-3300Hz, give or take. It's more than enough to pass clearly understandable human voice, but neither it is the same as being next to someone.
There are also a lot of the high frequencies present in the sort of transients that cymbals and snare drums and such put out - and I'll suggest that most audio compression algorithms mangle them quite badly until you get up into the lossless or "may as well have used lossless" bitrates.
Play with it yourself - record various notes, on various instruments, do the FFT to break it into the frequency domain, and you'll see quite a few harmonics over the base note. Strip those out, and it sounds muddy.
For those old enough, an analog phone line was typically limited to 300-3300Hz, give or take. It's more than enough to pass clearly understandable human voice, but neither it is the same as being next to someone.
There are also a lot of the high frequencies present in the sort of transients that cymbals and snare drums and such put out - and I'll suggest that most audio compression algorithms mangle them quite badly until you get up into the lossless or "may as well have used lossless" bitrates.